In order to cope with the requirements in the communication with a further high-speed and large capacity of mobile communication devices typified by smart phones and tablets, the MIMO technology (Multi-Input Multi-Output) using multiple frequency bands at the same time is beginning to be put into practical use. If the frequency bands used for communication increase, high frequency components are required for each frequency band respectively. Thus, in order to increase the number of the components while maintaining the equipment size, further miniaturization and higher functionality of each component is required.
As such electronic components corresponding to the high frequency, there are components such as a diplexer, a band pass filter or the like. They are all constituted by a combination of dielectric materials functioning as capacitors and magnetic materials functioning as inductors. However, it is required to suppress the losses respectively under a high frequency region in order to obtain a good high frequency property.
Regarding to the dielectric materials, in order to improve the selectivity of frequency, the dielectric loss is required to be small, that is, the Q value is required to be high. Many technologies have been disclosed on materials having low dielectric loss, among them, it is known that a material containing MgO has a low dielectric loss even under a high frequency band (2 GHz), that is, the Q value is high. Thus, the material containing MgO is one of the materials which are highly expected as dielectric materials used in a high frequency band.
Patent Document 1 discloses a technique relating to a dielectric thin film having a composition represented by a formula of xTiO2.yBaO.zMgO with an average film thickness of the dielectric thin film of 0.1 μm to 10 μm. A good temperature property and a high Q value can be realized by controlling x, y and z.